Depression: Beck Depression Inventory (BDI-II). This widely accepted questionnaire measures the severity of symptoms of depression. It was updated in 1996 in order to meet the criteria of the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition). The participants are asked to relate to 21 items that describe different depressive symptoms on a scale of 0-3. A general score on the questionnaire can therefore lie between 0 and 63 (a higher score indicates greater severity of depressive symptoms).